Spade and her husband founded the eponymous handbag brand in 1993. It now has more than 315 stores globally and sells clothing, activewear, jewelry, home goods, eyewear, baby items, and more. Coach bought Kate Spade for $2.4 billion last year.

The brand's popularity and value stems from its legacy of bringing personality without pretense to the luxury goods market. While other luxury handbags might be emblazoned with logos or just boring, Spade established the brand's aesthetics early on as "less serious, more personal."

Spade was no longer involved in her namesake brand by 2006. But the Kate Spade Spring/Summer 2014 collection shows how the the brand's original aesthetic continued. Eric Thayer/Reuters

Founded in 1993, Kate Spade New York was unlike the grungy aesthetics of the '90s. Spade herself was frustrated by the era's stiff designs, which she told The Boston Globe in 1999 failed to balance functionality and fashion.

"Handbags should be both. That's what designers were forgetting," she told the Globe. "So many bags can hold a kitchen sink but they're just big black bags."

One of the most iconic designs was The Sam, released in 1993 as a boxy nylon tote. It quickly became a cult favorite.

One of Kate Spade's most-loved designs is the 'Sam' bag, released in 1993. Here's what the original looked like.Courtesy of Nordstrom

While colorful nylon totes seem like a given today, the handbags were unusual when they first launched. The first line was barred from consideration for a trade show because it lacked leather, according to the 1998 Forbes article.

"She knew what the fashion world needed before we did," Joe Zee, the former creative director of Elle and former fashion director of W, told The New York Times following the announcement of Spade's death. "Kate just did what she felt was right, regardless of what the industry would think."

The husband-wife duo hadn't been involved in the brand since 2006, when they sold their remaining 44% stake in the business to Neiman Marcus for $59 million. Neiman Marcus already owned the 56%. Months later, Fifth & Pacific (then known as Liz Claiborne) bought Kate Spade New York for $124 million, and it's now owned by Coach parent company Tapestry.

The brand's Instagram account shares photos of white toast covered in rainbow sprinkles, boxy Kate Spade totes with candy or flowers peeking out, and quotes like, "She has a way with words, red lipstick and making an entrance."